How to: Obtain and Modify Selected Rows

• Nov 13, 2018
• 2 minutes to read

This example demonstrates how to obtain selected rows, and then change values of their “Discounted” column cells.

If Grid data is sorted or filtered, changes made to one Grid row can make other rows change their order and, as a result, their row handles. For this reason, you cannot access selected rows by their handles and process these rows right away. Instead, pass row handles retrieved by the ColumnView.GetSelectedRows method to the ColumnView.GetDataRow method. This allows you to access underlying data source objects (in this example, DataRows), save them to an array, and safely change their values afterwards.

Each row modification forces the Grid View to update itself. Enclose your code with the BaseView.BeginUpdate and BaseView.EndUpdate method calls to avoid excessive updates. Refer to the Batch Modifications Overview document for details.

C#

ArrayList rows = new ArrayList();

// Add the selected rows to the list.
Int32[] selectedRowHandles = gridView1.GetSelectedRows();
for (int i = 0; i < selectedRowHandles.Length; i++) {
    int selectedRowHandle = selectedRowHandles[i];
    if (selectedRowHandle >= 0)
        rows.Add(gridView1.GetDataRow(selectedRowHandle));
}
try {
    gridView1.BeginUpdate();
    for (int i = 0; i < rows.Count; i++) {
        DataRow row = rows[i] as DataRow;
        // Change the field value.
        row["Discontinued"] = true;
    }
}
finally {
    gridView1.EndUpdate();
}

VB.NET

Dim Rows As New ArrayList()

' Add the selected rows to the list.
Dim selectedRowHandles As Int32() = GridView1.GetSelectedRows()
Dim I As Integer
For I = 0 To selectedRowHandles.Length - 1
    Dim selectedRowHandle As Int32 = selectedRowHandles(I)
    If (selectedRowHandle >= 0) Then
        Rows.Add(GridView1.GetDataRow(selectedRowHandle))
    End If
Next
Try
    GridView1.BeginUpdate()
    For I = 0 To Rows.Count - 1
        Dim Row As DataRow = CType(Rows(I), DataRow)
        ' Change the field value.
        Row("Discontinued") = True
    Next
Finally
    GridView1.EndUpdate()
End Try

Run Demo: Obtain Selected Rows